Format: Android devices
Pricing: Free

Description:
ChordTouch is a simple app for android which plays sampled piano chords. In a 2-step touch process, the user first selects the desired root note, and then selects a chord quality to hear the resultant chord. Within a given key, all 7 diatonic pitches can be used as root notes. To change the key, simply tap the white key button on the bottom right corner, and any of the 12 major keys, plus their relative minors, can be selected. The diatonic root notes will change accordingly.

A variety of chord options exist, including major and minor triads, all five seventh chord types, first inversion triads, a 4-3 suspension, and even 9th chords. Although it is tricky, chord progressions can be created and played by stringing together multiple chords, changing the root pitches accordingly. 

Features:

• Chord generation in all 12 major or minor keys
• Single tone mode
• Ability to modify the chord layout

My Experience:
ChordTouch's key benefits are ease of use and a simple layout. Furthermore, the chord options included will cover and correlate with the vast majority of music that students hear and experience. The chords in ChordTouch are applicable to rock, pop, band, orchestra, and choral music among others. Only advanced jazz or advanced music theory students are likely to notice and be detracted by the chords not available in ChordTouch. The interface is very simple and easy to use: pick a root, pick a quality, and boom, you get a nice piano chord. Change the key if you want to. 

ChordTouch's simplicity is also its downfall. The piano sample sound is nice, but it gets boring and repetitive after a short period. This will be a negative for users of other apps that include the ability to change the output sound. A lack of octave transposition limits its functionality - low register singers or instrumentalists may find this a detracting factor. With all the keyboard apps available, ChordTouch's single tone mode is basically useless.

I would not recommend ChordTouch for any kind of performance or accompaniment situation. Although the interface is easy to understand, it does not lend itself to playing chord progressions quickly or smoothly. By nature, the two step selection process of root, then quality produces awkward transitions between chords, regardless of how much you practice or how fast you get. The video above is a good example. 

Pros:

• Simple, easy to use interface
• Good variety of chords to choose from
• Free

Cons:

• Two step process is hard to do smoothly and quickly
• Piano output sound only
• Layout of diatonic root notes (purple buttons) does not change for minor keys
• Cannot transpose octaves; higher octave tonic chord (built on scale degree "8") is unavailable
• Difficult to figure out how to alter the chord layout

Final Thoughts & Verdict
ChordTouch could be a useful tool to aid in introducing or reviewing chords and their different qualities. It could be used for brief ear training exercises; the teacher could play chords and quiz students on their quality, or students could test each other. The app's limitations quickly become apparent, and I believe most users will find other apps that can do everything ChordTouch does, plus a lot more. 

However, since it includes so many chords students hear every day, the interface is simple, and its free, ChordTouch is at least worthy of mention to students. They may find creative uses for it (they could try to figure out and play the chords to their favorite pop song), and even if they only use it to play around in their free time, at least they will be thinking about and listening to harmonic functions.   

Format: Website formatted to use mainly flash player exercises though non flash games are available too. Mobile version of the website formatted for android and iOS though some functions to not operate fully on iOS devices. 

Pricing - Absolutely free. Except whatever Comcast is gouging you for rates. 

Description: Teoria is a music theory resource site that has both tutorials for teaching a wide variety of music theory concepts, as well as very customizable exercises to compliment the sites tutorials. There is also a large resource page that provides definitions, articles on music theory, history, composers, and analysis. 

Features: 

• Interactive lessons on virtually all music theory subjects
• Customizable exercises to compliment lessons or stand alone from them
• Excellent pool of resources to aid in research 

My Experience: 
I have used this website since 2011 and I always find a way to integrate it into my classes. While I mainly utilize the exercises as in class activities and assignments, it is great to be able to have a free site available that can be a resource for your students and yourself. The site is very easy to navigate, and they are constantly updating it to make it better, more user friendly, and adaptable on mobile devices. The nice thing about the tutorial section is that it is laid out like most theory books are, but the examples that they give can be expansive and interactive. They aren't just comparison pictures of examples, but moving, audible examples of what they are teaching.

(Optional demo/screenshot would go here)

Pros

• Covers a range of topics from very beginning to advanced theory
• Tutorials give interactive examples to compliment text
• Runs smoothly with little loading time  for lessons and exercises
• Exercises are customizable from the load screen to cater to different mastery levels
• Easy to use
• Great resource articles 
• Now useable on most mobile formats as well

Cons 

• Some exercises don't work/work well with iOS devices-though they constantly update
• Percentage on the exercise pages doesn't show amount of tries for the exercise
• Tutorials section can be tricky to navigate for first timers (mess with it a bit first)

Features (intent of program)

Final Thoughts: 
I really enjoy this website. I know that there are a lot of music theory based apps and sites out there, and I personally think that this is one of the best. First of all, it has a great way of being a lesson aid, or supplementing materials that you use in class. The materials the student(s) will be working with are interactive and provide several examples on how to understand the concepts better. Second, as a tool in the classroom the endless customization of the level of concepts that you can control are fantastic. They can make for great in class exercises, or homework. While the time stamp and percentage can be "beaten" by a student by only doing the exercise a small amount of times, the concepts can still be checked later by the teacher. Final thought is that this is a site you should have in your repertoire and find how to utilize it best for your own class. It's flexible, and it works.
 Use it.

Format: Web browsers (for full website)
               iOS devices (for Tenuto and theory lessons apps)

Price: Free for web features
            $2.99 for the theory lessons app
            $3.99 for the Tenuto trainer and exercise app

Features:
Musictheory.net features interactive music theory lessons on topics ranging from the introductory (staff, clefs, duration values) to the more involved (keys, scales, and triads) to the advanced (inversions, chord progressions, and melody harmonization). The lessons allow students to work at their own pace and include audio and visual enhancements. Interactive trainers allow for practice and drill on a variety of skills, including note identification, scale, chord, and interval identification, key signature identification, ear training, and more. The difficulty and complexity levels for each exercise can be customized for each student or class.  

This resource is valuable to music educators as it it can benefit students at all levels of music education, from beginners to high school or adult learners. See the images below for an idea of the wide span of content covered on musictheory.net. It can benefit musicians in all performance mediums, as the theory concepts are universal. All of the features can be accessed for free on a web browser, and the exercises and lessons can each be accessed via their respective apps on iOS devices. 

Personal Experience:
I have been able to use the features of musictheory.net in a wide variety of settings. The lessons and trainers work well with beginning musicians as they are learning the fundamentals of music notation and note names. With more accomplished musicians, the key signature, scale, and ear training drills can further improve their skills. Students who need remedial work in music literacy can refine their abilities, even off to the side during ensemble class, with exercises tailored to their needs. I have used the exercises with beginning level and intermediate level students, and in both one-on-one lesson and full ensemble contexts. We turn it into games and see who can score the highest on each drill. I have also put exercises up on our classroom Smartboard, lined the students up single file, and had a "knockout" style elimination competition, which they get a kick out of. Several students have enjoyed the activities so much that they have put the apps on their own devices.  

The lessons are especially beneficial for any type of music theory class, as the concepts start at the very basic and progress to the fairly advanced. Even at the level of an AP Music Theory course, the lessons on www.musictheory.net can be a great asset to students for many of the concepts covered throughout the year. The drills in scale, interval, and chord identification and ear training are especially beneficial in preparing for the AP Music Theory exam. 

Final Thoughts & Verdict:
www.musictheory.net is a GREAT resource for music educators at any level. It cannot provide an entire curriculum or an entire class worth of activities, but the lessons and trainers are fantastic supplements for any music class or lesson situation. The complete customization of any trainer exercise allows for each student to have an individualized experience, which is incredibly valuable. Music learners of all levels can find some sort of benefit with this resource. Even if students only need help with one concept, such as key signatures, a lesson or exercise can be found to accomplish the goal. Free access to the web version, uncluttered by ads and other junk, is an incredible value. Those who feel urged to support musictheory.net can pay the small app cost.