A free program for Android, by ETenses.
ETenses - A learning app for irregular verbs, that is designed to solve two problems:
Learning verbs for the first time in the past, present, and future tenses.
The ETenses app works as follows:
Each verb has a separate section in the application, where you will be able to choose the past, present, and future tense, with explanations of how they are related to the time.
Each verb has its own unique visual representation on a timeline that includes a line showing how the verb is connected to the present time.