Creating a simple interface is not enough to make a custom tool. The biggest challenges typically include performance, stability and correct testing, particularly when supporting multiple platforms such as Windows, Android and iOS.
Tools like delta-executor show why lightweight design, regular improvements, and good script handling are important for a smooth user experience. If you’re hiring a developer for this type of project, I’d recommend checking their previous work with Lua scripting, application development, and security practices. A clean code structure and long-term maintenance plan can make a huge difference for the success of the project.