Now this is a really professional app. It’s got lots of verbs, and all the forms are here, very clearly arranged.
I can suggest one heroic enhancement: could it be made searchable by any verb form, so that the user could look up any mysterious word he comes across to find out what verb it is, and what form? That would be really useful. As it is, the search works only to find an infinitive in the list. The problem for the learner is hitting unrecognizable forms and trying to guess what they are.