How long does it take to make an app?
Time of app development
As in the case of evaluation of the cost of mobile app's creation, during telephone talking it can be said only exemplary time of project development. They are taken from experience of similar mobile apps' creation.
For example, development of mobile app for iOS or Andriod, showing reference data about organization and not demanding feedback (catalog of products with the possibility to order by phone without any registration of users and personal room), is taken less than one month. But the term of creation of social network with base functional for two platforms - about 2 months of work. Precise evaluation of terms is possible during detailed discussion of technical task for mobile app's development.
Risks in time estimation
Any evaluation of terms of mobile app's development can be not precise for any reasons. Some changes can be included in the project during the realizations. Besides, in the case of mobile app's development for iOS, where checking mobile apps is demanded before including in App Store, some nuances are possible, which can influence on the date of app publication.
In this case it should have enough time for mobile app's creation between finishing of app's development and marketing start: if the date of project finishing is the 1st of January, it doesn't need to plan the start of marketing campaign on the 5th of January, it is better to defer it for 3-5 weeks. But the main and frequent factor, influencing on terms of app's development, is project changes during the process of its realization. Mobile app is complex product, and it is difficult to take in account all the aspects of it.
Developer, basing on his professionalism and experience, evaluates all possible situations, but he doesn't know all the nuances of client's business-logics, and if on the some level it is necessary to add information in the profile of user about his post address, so it will take some additional time for realization of this functional, that will influence on terms of mobile app's creation.
It is possible to minimize these risks to give enough time for analysis of business-logics and the structure of mobile app: if firstly maximal amount of all the nuances can be discussed, so risks to face to some problems decrease.
The responsibility of the parties while respecting the terms of mobile app's development
Responsibility of developer and client is an important moment during project work. Mobile app is always collective work, both parties are involved in it, so responsibility for respecting terms is mutual.
Very often in the cases of internal or external reasons developers say that delays are inescapable on the certain level of development. There is no something terrible in it: for example, if during realization of link with any payment system some problems appeared, it wouldn't be predicted, you just know about this possibility. But you should take necessary measures immediately, if you can't see real reasons for term delays from the side of developer and you were not notified about them.
Another situation is possible: developer informs client about certain level of development on schedule, but he has to wait for checking not for three days, as it was discussed, but for two weeks. This moment is as so uncomfortable for developer, as uncomfortable for client delays from the side of developers: on the one hand, schedule of app's development should be changed for not losing working time, and on the other hand, there is no possibility to solve another problems, because client answer can be received in any time, and works should be continued depending on this answer.
For respecting development's terms it is important to be responsible for discussions, decisions and realization from both sides.