Count the omer with R. Yaacov Haber’s Sefiros iPhone and/or iPad app: link
Spiritual refinement through counting the omer: A practical 49 day guide to spiritual refinement through counting the Omer and the cycle of sefiros.
This is a free version of the app. There is also a paid app.
Here is another free iPhone/iPad app for counting the omer: link
Here is a free Android app for counting the omer: link