A mobile application, also referred to as a mobile app or simply an app, is a computer program or software application designed to run on a mobile device such as a phone, tablet, or watch. Apps were originally intended for productivity assistance such as email, calendar, and contact databases, but the public demand for apps caused rapid expansion into other areas such as mobile games, factory automation, GPS and location-based services, order-tracking, and ticket purchases, so that there are now millions of apps available. Apps are generally downloaded from application distribution platforms which are operated by the owner of the mobile operating system, such as the App Store (iOS) or Google Play Store.
Thank you for your question. There is no problem in doing that.
May you always be successful
We can not confirm that every compass is accurate nor every application is accurate. You need to check more than one compass or application when you have doubt.
You can also check the direction of sunrise or sunset which can help in many places.
Yes it is permissible as far as you do not help or propagate harmful or sinful applications or products.