It is first application for android which works as it stat but it is premium software and providing 30 days trial. After it, you need to purchase full version.
If you do not buy and do not uninstall then you would not be able to do after trial period.
Only solution is to hard reset your mobile with using keys combination. You need to switch off your mobile and use key combinations to format it.
Do not have key combinations?
You can search on Google, search by your model name and type hard reset keys.