Extremely simple; works with iTunes IPSW files. Cons: Expensive for the full version ($49.95/year); fewer advanced options.
Your iPhone shows the Apple logo for hours. iTunes recognizes the device but fails to restore after downloading the IPSW. A flash tool can re-partition the NAND and force a clean install. iphone firmware flash tool
Free, frequent updates, massive IPSW database. Cons: Windows only; no native macOS version. Extremely simple; works with iTunes IPSW files