Ask HN: Crawler for my app. Please suggest

Have a look at import.io as long as you're dealing with a small set of pages, e.g. ecommerce.

(I note you asked about git 2 weeks, then which programming language to use, then native vs html app, then which test framework to use, now which crawler to use. It makes it sound like you didn't do research on your own)

You could try out http://scrapy.org/.

Not sure what you are asking for, a crawler, or a website to be crawled.