This app has a timer function. When setted time passed the light will be turning off and also app will be finished automatically if you wish.
If you don't like an ad, you can turn off ad's displaying with payment. See setting's menu.
* The network access's permission is used for an ad display and Twitter.
Author is Japanese, so sorry for my poor English.
If you want to improve English strings in app or you want to replace app's strings to your language, contact me and help to translate for me, please.