One of the biggest problems in the community is the spread of STDs. People who engage on NSA fun sometimes to not worry much about warning others if they tested positive on STDs due to shame or other reasons.
To avoid more people getting infected and others start treatment as soon as possible, it would be great if the app offered a function to alert someone that he has been at risk with another person. This is done already by clinics, but you need the phone number to text anonymously the other person.
Grindr could create a function that when you enter a profile, you can alert someone about this. The person alerting would select the std they got tested possitive frok to let the other person know. This information should not be tied to a profile or saved anywhere for data privacy.
The person receiving the alert would receive a predefined message saying a person they have been in contact with has tested possitive for the chosen stds. Ideally, with the message, it should offer some links or resources about the disease and near clinics to ask for treatment depending on the region.

This would really help the community be safer and healthier.