Battery Alerts lets you set a target level that, when reached, will trigger a notification.
This way you can avoid check repeatedly the charge level of your phone to know if it has reached the level you wish; just set a target level, start the service, plug your phone and you can be sure that you will be notified!
For any information, problem or if you want to request a new feature, send an email to feedback.advancedalerts@gmail.com