I didnot find any kobocollect ap in iphone. Please guide me

Welcome to the community, @dhulikhel601! Kindly be informed that KoBoToolbox currently only offers the KoBoCollect android app for collecting data that can be downloaded from the google play store. However, you could still collect data through an IOS device via Enketo aka web forms. To learn more on the same, please feel free to have a look at our support article WHAT ARE ENKETO WEBFORMS? and COLLECTING DATA THROUGH WEB FORMS.

You should, however be able to use Collect android app in your iOS or Windows platform through this Android emulators for PC and Mac that have been discussed here: