Hi Mohammed,
Johannes from langify here.
langify allows you to translate your products, pages, blogs, blog post, theme, etc.
Also langify allows you to translate your checkout page (except the product which will always only show up in your base language).
Also, langify is probably the best choice in terms of SEO.
What langify does not do (compared to the other apps) is doing the translations for you. That is, using langify you must translate your content manually.
If you are looking for automatic machine translations you should have a look at the Google Translate Widget. It comes for free and shopify has a doc on how to integrate it available here.
If you need any more informations please feel free to contact me directly via support@langify-app.com
Best Regards,
Johannes