Start Cheap

• get Mac OS X virtual machine running on pc, install Xcode, develop and run emulator
• use other tool to push no certificate ipa to a iOS device temporarily

No Way to Get Around It

• soon or later, you still need to get a real mac, a iOS device, and yearly paid developer account certificate

All about that yearly paid developer account certificate

• the only way you can easily push your app to more iOS devices without pain.

Outsider

• free
• only work on device with same Apple ID signed

Normal Level

• 99 USD per year (free for non-profit, government)
• can be set on Individual (your name) or Organization (Company name)

Apple Developer Enterprise Program

• 299 USD per year
• closed environment developers, for non-distribution app development

iOS Developer University Program

• free
• for school teaching iOS programming

ref: https://developer.apple.com/support/compare-memberships/

• you need to worry more than just what you programming, that is code signing, app verification for distribution, the process that apply to both android and ios for device security
• mobile device are more sensitive to security than PC, which anyone can write anything to run anywhere, since PC hardware are out of controls from single company, while mobile device are all-in-one device and can be secured or limited by a single company, both software and hardware level.

• to read
  • https://medium.com/ios-os-x-development/ios-code-signing-provisioning-in-a-nutshell-d5b247760bef
  • https://engineering.nodesagency.com/articles/iOS/Understanding-code-signing-for-iOS-apps/
  • https://www.oreilly.com/library/view/essential-ios-build/9781449314781/ch01.html

• iFunBox: a free win/mac tool to push and manage ipa from computer to iOS device
  • http://www.i-funbox.com
• handshaer: a free win/mac tool to manage apk from computer to android device
  • https://www.smartisan.com/apps/#/handshaker