Apps for rhythm and ear training

Let's have a discussion about good apps for ear-training, rhythm, and theory. 

Harp Column magazine had a good article on this.  but you need a subscription to read it. 

Here's another good page to peruse for ideas: 

Elisa Thorn recommended this one 

These are three of the apps mentioned in the Harp Column article. 

Beat Drills 

Type: rhythm practice 
Clapping Music 

Type: rhythm practice 

Meludia Melody 
Type: ear training 
Elizabeth Volpé Bligh