The tool was downloaded and set up by over 1M users and the most recent stable release was on Aug 4, 2012. This application displays adverts. Samsung and LG users recommend the app.
A free .apk installation package of 100 Doors GUIDE 1.0.7 is available from Droid Informer and you can check out users' reviews on this site. Prepare 2 MB of free space on your device for this app installer and keep in mind that it runs on Android 2.2 and above.
From the users' point of view, the app has such a disadvantage as spelling and grammar errors.