Important Considerations

You should know what you want: Business requirements must be ‘complete’ (no ambiguity) because technical requirements would be derived from them. Changes in business requirements will change technical requirements and that would most certainly will add time to development and of course cost.
Your selection of the model to develop the product depends upon how you will manage (record, assess) the business requirements.
Ask your developer/technical team to make the code as generic as possible. Avoid hard-coding wherever possible.
For a startup cost may be a barrier to run & operate a full featured mobile app. In such cases we recommend to go with the approach of first developing a MVP (Minimum Viable Product) which technically means to have the minimum feature sets that would be required to run the operations successfully (easy for you & customers to use and starts to create your brand value).
- Next, in this approach, is when the start-up is ready (either by generating profit or getting funded), the next set of features can be developed & deployed for operations.
No product is complete without being launched and worked in real-time environment. Your requirements might change or new requirements get added with time.
Code must be kept safe. Use a centralize source code version & control system. This will allow you to switch back to a version in case of technical challenges & it also manages and stores revison of repository.
You should have in-house technical team that understands & can work with the technology used in the development of the product or else you would need an AMC with a third party.
If you have paid for the product then you must file & own its patent.
Unplannned downtimes by the hosting provider should be minimized. So in order to mitigate you can go for Private Servers but the cost of running them would be too high. If you wish to minimize the cost then you can go for VPS, but beware of the downtime that occurs which can lead to loss of business.