Thank you very much for this feature request. We have something like it on our radar already with plans to implement it sometime for a future release. The way we plan to implement it is to have a custom field where you can set pre-defined values to choose from as new records are added. In this implementation, you would only be able to choose either Windows or Mac or iOS, etc., because the options would be stored in a dropdown, you wouldn't be able to choose more than one platform to associate with the record. To do that, you would have to add more fields and select the platform needed. However, if we get more interest in people wanting a checkbox type feature allowing for multiple selections, there would be the possibility of implementing that as well.
From time to time it would be handy to have a checkbox or list for fields in custom record types.
An example, for myself, and a custom (computer service) "Client info", a "Computer type" field might have checkboxes (or a list) to select "Windows" or "Mac".
From a search point of view; the searchable value would the string value of the checked box (or selected list item).