It exists, sort of. There's a "halal search engine"[1]. Iran has something like the Great Firewall of China.[2] Saudi Arabia has official censorship, and they're open about it; there's a web form for requesting that something be censored, and blocked sites divert to a page saying it's blocked.[3] It seems that Iran's system is fairly tight, but the Saudi system isn't really that strict.
On the other side, there are multiple "kosher ISPs" with cloud-based filtering. There are even "glatt kosher" ISPs.[4] "The Secured program will block pornography and violence; Secured Plus will also block women wearing intimate apparel; Secured Squared and Protected will filter out any immodest clothing; and Sealed will enable access only to sites with religious and modest content." In Israel, there are "kosher phones", which are either voice only or can't access the web at all. They just run rabbi-approved apps.[5]
Anecdotally, VPNs are incredibly popular in Iran and the government hasn't had a great deal of success in blocking their usage. Unlike the Chinese GFW, the government entities in Iran that want to run a nationwide firewall are not able to attract the 'best and brightest' network engineers. The sort of Iranians who might be qualified to implement such are not living in Iran, they're living in Los Angeles and working for six-figure salaries in US dollars.
An important note regarding the "kosher" ISPs - they're opt-in. Anybody who has an account with a "kosher" ISP is free to cancel and get an account with an unrestricted ISP. That makes them qualitatively different from Chinese etc. ISPs where people have no choice but to submit to censorship.
On the other side, there are multiple "kosher ISPs" with cloud-based filtering. There are even "glatt kosher" ISPs.[4] "The Secured program will block pornography and violence; Secured Plus will also block women wearing intimate apparel; Secured Squared and Protected will filter out any immodest clothing; and Sealed will enable access only to sites with religious and modest content." In Israel, there are "kosher phones", which are either voice only or can't access the web at all. They just run rabbi-approved apps.[5]
[1] https://www.rferl.org/a/internet-searching-islam-halalgoogli...
[2] https://www.dailydot.com/news/hewlett-packard-iran-censorshi...
[3] https://freedomhouse.org/report/freedom-net/2017/saudi-arabi...
[4] https://www.ynetnews.com/articles/0,7340,L-3446129,00.html
[5] https://www.haaretz.com/jewish/.premium-israel-unveils-koshe...