- the FULL cash transaction of the purchase with bank statements backing it up
- CPF payments for 3 employees (at least pay for 2-3 months before even making the purchase and claiming)
Try elance or if you have the budget, I would recommend just googling for app developer in Singapore.. Quite a lot of firms do mobile apps now and you can meet up with these businesses to discuss your requirements.. It is not necessary to outsource to overseas when you get quality, reliability & acc...
If you make a lot of money, then going for Dividends would be best, Singapore has Pte Ltd tax benefits as well as max corporate tax of 17% instead of personal income 20%