PhotoGramm

PhotoGramm is a photo competition.
You can download the app for free in the store (iOS or Android). You have to accept the terms of use - e.g. that the photos are owned by the organizer - and you're ready to go.
Fans can get their best photos (beautiful moments, selfies, sports events, entertainment / cultural events, ..) awarded.
With the app, photos can be taken and stored in a cloud gallery. Photos taken outside the app can also be uploaded to this gallery. This can be done by means of "share function" in Android or "export function" in iOS and the selection of the PhotoGramm icon.
Depending on the organizer, the photos can be augmented with brief information at the bottom of the picture. This can be the logo of the event, date, the current score / race result, etc.
The fan is then invited via a notification to a photo contest - Challenge -. Depending on the organizer, one to several winners can win a prize in this challenge. The notification includes the name of the organizer, possibly the sponsors, the number of winners, the prizes for the winners, the duration of the challenge.
When invited to the challenge, the game mode will also be announced. Eg: that the photo with the most "likes" wins. The fans vote themselves, in the app either via the voting button "likes" or "dislikes" (thumbs-up or thumb-down icon).
The photos are checked in the back-office system of the organizer for compromising content. Such identified photos are eliminated.
Depending on the organizer, the photos can also be shared by the fans in the social media.
Have fun!