Powershell ISE is described as 'The Windows PowerShell Integrated Scripting Environment (ISE) is a host application for Windows PowerShell. In Windows PowerShell ISE, you can run commands and write, test, and debug scripts in a single Windows-based graphic user interface with multiline editing, tab completion' and is a IDE in the development category. There are four alternatives to Powershell ISE for a variety of platforms, including Windows, Linux, Mac, Web-based and Chrome OS apps. The best Powershell ISE alternative is Visual Studio Code, which is free. Other great apps like Powershell ISE are Lapce, PowerShell Studio and PowerShell Plus.
Visual Studio Code offers a good support of PowerShell (through extension). It provide integrated terminal, debugger and even a "PowerShell ISE" mode that mimics the look and feel and behavior or PowerShell ISE. Official documentation of PowerShell feature : https://code.visualstudio.com/docs/languages/powershell