Here's one use case: you're at a conference and you meet a person. You get along great and you see yourself becoming friends.
In normal circumstances you'd try and keep in touch through email or social media but as time goes on and you both get busy with your lives you lose touch.
Luper helps you remember to keep in touch with people. With Luper you'd add that person to say a quarterly time lup and every 3 months you're reminded to contact that person by either phone, email, or text. You can also add notes to that lup (what you talked about, how you met, a follow up item).
Luper has one purpose, to help you remember to stay in touch. This applies to personal relationships and professional relationships.