Android is not an option for FileMaker and what you describe short of setting it up on a webserver and having them access it via a web browser.
Any FileMaker file of recent version can be copied to an iOS device such as an iPhone and opened in FileMaker GO--which is a free app.
There is an iOS SDK tool that can be used to set up an app from the FileMaker solution that does not require FileMaker Go.
FileMaker Advanced can be used to create a run time version of your solution for deployment on Mac and Windows devices that do not have FileMaker installed. Run times have certain built in limitations and deployment on Macs takes a bit more jumping through hoops so you need to research this option if you choose to use it.