Primal has one, I build one one time where you could download the days to a file then upload it again but I lost the code.
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nostr:nprofile1qqs9map4g4l4ewzdp6jn3zhml58j4zr8kkm2wl8hnxmz9ksfyyma3jgpz4mhxue69uhhyetvv9ujumt0wd68ytnsw43qz9nhwden5te0wfjkccte9ehx7um5wghxyctwvsg64r4l auto backup your muted list and following list for 7 days