My question is about financial rewards and compensation.
There is a Smartphone app for iPhone and Android called GymPact. Basically you agree to doing a certain number of workouts/exercise per week, and you set a penalty e.g. $10 for each workout you don’t do. So for example, you could say I will do 3 workouts next week, and for each workout I miss, I will pay $10.
If you manage to do all three workouts, then you get a reward, between $0.50 and $0.75 for each that you did. This is paid for by those people who did not manage to do their workouts and had to pay the penalty.
Is such a system permissible in Islam?
In the name of Allāh, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykum wa-raḥmatullāhi wa-barakātuh.
Since we do not have the original document or contract which a person signs when joining this program, it is very difficult to correctly classify this transaction.
From the information that is available, the program can either be a “pact/promise” or an enforceable “contract”.
a. Pact/Promise :
This program can based on an essential concept of promise, i.e. “A” enters a promissory clause that if he does not fulfil the required number of workouts in specific days, then he promises to give $10 to the Gympact. In this case, the promise has to be voluntary such that if “A” chooses not to give the $10 to Gympact, there will be no liability on “A” and Gympact will have no legal recourse to take that $10.
Similarly, Gympact can enter into a separate promise stating that should “A” complete this task, Gympact promises to voluntarily give “$0.50”. In this case, “A” will not have any legal right towards the $0.50; rather rely on Gympact to fulfil its promise.
The above set-up is correct according to Shariah.
b. Combination of an enforceable “Hiring” Contract and a promissory clause.
Gympact can enter into a hiring contract with “A” stating that “A” must do certain number of workout in certain time duration, and they will be paid $0.50. In this case, it is important that the payout must be clearly mentioned before the completion of the task and not left ambiguous. If it is left ambiguous then the hiring contract will be impermissible.
Along with the above contract, “A” enters a promise that should he not complete his task, he will voluntarily give $10 to the Gympact. Once again, the voluntary promise means that the Gympact has no legal right to take these $10 should “A” choose not to give.
Such a set-up will also be correct according to Shari’ah.
c. Enforceable contract of hiring with penalty.
The program can also be set up in such a way that Gympact enters into a hiring contract with “A” to do certain amount of workouts in return for a $0.50 per workout. The amount will have to be determined before hand and not left ambiguous. And along with this Gympact puts a condition on “A” that lack of completion of the task will be charged with a penalty of $10.
Such a contract is not Shariah Compliant.
And Allah Ta‘ālā Knows Best
Mufti Faisal al-Mahmudi 
Checked and concurred by
Mufti Luqman Hansrot