Comparison

Spark Mail vs SuStash

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Spark Mail

Streamline your email and calendar management with an AI-powered assistant. Organize multiple accounts, declutter your inbox with smart sorting, and use AI to draft replies, summarize threads, and manage your schedule efficiently.

Highlights
  • Unified inbox for multiple email accounts
  • AI-powered email summarization and drafting
  • Smart Inbox for prioritizing emails
  • Calendar management and meeting scheduling
  • Gatekeeper for sender screening
  • Team collaboration on emails
  • Integrations with productivity apps
Features
Read full description

Manage priorities, not emails. Spark brings every account into one inbox and automatically surfaces what matters most — so nothing slips through the cracks. Loved by millions and named "Best of the App Store" by Apple. "It's a combination of polish, simplicity, and depth." — FastCompany "You can create an email experience that works for you." — TechCrunch EVERY ACCOUNT, EVERY EMAIL, IN ONE PLACE Connect Gmail, Outlook, iCloud, Yahoo, AOL, Hotmail, GMX, and any IMAP account in a single unified inbox. STAY ORGANIZED WITH SMART INBOX Important emails from real people rise to the top. Newsletters and notifications stay neatly grouped below, out of your way. GET MORE DONE WITH EMAIL ESSENTIALS Mark emails as done or set them aside for later Mute threads you're no longer following Schedule emails to send later — even if your device is off Find anything fast with Smart Search and Smart Folders PROTECT YOUR INBOX WITH GATEKEEPER Pre-screen new senders and block unwanted contacts instantly. PRIORITIZE WHAT MATTERS Mark important senders so their emails always stay on top. Group emails by sender or domain to keep your inbox clean. WRITE FASTER WITH SPARK +AI Summarize long threads, draft replies, rephrase messages, and adjust tone. Your AI Assistant helps you clear your inbox, translate emails, and keep projects moving. MANAGE YOUR CALENDAR AND MEETINGS Connect your calendars to stay on top of your day in one app. CONNECT YOUR FAVORITE TOOLS Link Spark to Notion, Asana, Things, and 10+ integrations to act on everything in your inbox. COLLABORATE WITH YOUR TEAM Co-author emails and discuss in private comments Assign messages so everyone knows who owns what Share secure links to specific emails Track read receipts to keep work moving SECURE AND PRIVATE Spark encrypts your data, runs on Google Cloud's secure infrastructure, and is fully GDPR compliant. TRY IT FREE Stick with our powerful free plan, or try Spark Plus or Spark Pro free for 7 days. Download Spark and reclaim your day. FAQ Is Spark the best email app for managing multiple accounts? Spark brings Gmail, Outlook, iCloud, Yahoo, and any IMAP account into one unified inbox, so you can manage every email in one place instead of switching between apps. How is Spark different from Apple Mail and Gmail? Spark helps you focus on what matters, not just read email. It automatically prioritizes messages from real people, keeps newsletters out of the way, and can summarize, draft, and follow up so less falls through the cracks. How does Spark help with email overload? Spark surfaces important messages first, lets you snooze emails until you're ready, and helps you reach Inbox Zero without the grind. Higher plans flag what needs attention so nothing gets missed. Does Spark have AI features? Yes. Spark uses AI to write faster, reply clearly, and summarize threads. On Plus, AI helps you make better inbox decisions. On Pro, it acts on your behalf — drafting, organizing, and following up. Is Spark good for team collaboration? Yes. Teams can share drafts, comment privately, assign messages, and manage shared inboxes — no forwarding chains. Collaboration is available on Pro. Can I schedule emails to send later? Yes. Schedule any email to send at the right time, or snooze incoming messages to return when you're ready. Is Spark free? Yes. Spark is free to download and use. Spark Plus is for professionals who want a more focused inbox; Spark Pro is for those who need Spark to handle follow-through so nothing gets missed. Is Spark available on Mac, iPhone, and iPad? Yes. Spark works on iOS, iPadOS and macOS, and stays in sync across all your devices. Spark is made by Readdle. Terms of Service: https://sparkmailapp.com/legal/terms Privacy Policy: https://sparkmailapp.com/legal/privacy-app Help: support@sparkmailapp.com

About

SuStash

Features
Read full description

SuStash is the fastest way to save, organize, and actually revisit the links you collect all day. Videos, articles, recipes, products, GIFs, and more. SAVE FROM ANYWHERE Share from any app. YouTube, Safari, Instagram, Maps, anywhere, tap SuStash, and you're done. Auto mode files the link into the right collection for you; Manual mode gives you collections, tags, and notes. You can also save straight from your clipboard or with a Siri Shortcut. ORGANIZED FOR YOU Every link gets a real title, a preview image, and a smart collection; Recipes, Music, Places, Tech, News, Shopping, and more. FIND ANYTHING AGAIN Search matches meaning, not just words. Browse your Library as collections, tags, or a media grid, and see your stash as charts. Saved links appear in iPhone Spotlight search too. REDISCOVER The Rediscover tab resurfaces what you saved and forgot: unopened links, favorites, and picks similar to what you actually open. An optional weekly reminder keeps your backlog honest. PRIVATE BY DESIGN No accounts. No ads. No tracking. No data collection — everything runs on your device. Your links are yours. SUSTASH PRO Go Pro to unlock: • Smart Filing that learns how YOU organize and files new links your way • Smart Suggestions in Rediscover • iCloud Sync across your devices, stored in your private iCloud • Extra themes with unique fonts and backgrounds • Export your entire library as JSON Monthly, yearly, or pay once for lifetime access. ALSO INCLUDED FREE Home-screen widgets, automatic organization, semantic search, statistics, list/grid/icon views, pinned collections, light & dark mode, and Shortcuts support. Stop losing links. Start stashing. Privacy Policy: https://abdelrahmantealab.github.io/sustash-legal/PRIVACY Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

Spark Mail4 screens
SuStash4 screens

Verdict

The call

The clearest difference is update cadence: SuStash at every 3 days against Spark Mail's weekly. Spark Mail's advantage is chart position (#115 vs unranked). On price, ads, in-app purchases and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Spark Mail sells 13 in-app purchases, starting at $7.99 per month and SuStash sells 3 in-app purchases, starting at $1.99 per month. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

Spark Mail ships an update weekly, SuStash every 3 days. The most recent releases landed on October 25, 2026 and October 9, 2026 respectively.

Scorecard2 real differences · 9 level
Spark Mail versus SuStash: the parameters behind the verdict, then further details
ParameterSpark MailSuStash
PriceFreeFree
Rating4.6 (83K ratings) — better—
Positive reviews61.1% of reviews—
Number of ratings83K — better—
Update frequencyWeeklyEvery 3 days — better
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchases—
Best chart rank#115 — better—
DevicesiPhone, iPad, Apple Watch — betteriPhone, iPad
Requires iOS16.4 — better17.2
Further details — not scored
Size392 MB4 MB
Age rating4+4+
DeveloperReaddle Technologies LimitedAbdelrahman Tealab

Bugs and requests

Spark Mail

Reported bugs

5 issues
  • Emails disappearing from the inbox
  • Delayed email delivery and sync
  • Crashes and freezes when opening the app
  • Issues with Exchange calendar and account sync
  • Incorrect email grouping and threading

Requested features

5 requests
  • Improved spam filtering and email blocking
  • Option to disable email threading
  • Better calendar integration and management
  • Customizable email signatures and layouts
  • Expanded third-party app integrations

SuStash

Not enough reviews yet to summarise bugs or requests.

In-app purchases

13 purchases

Spark Mail

Subscriptions10
  • Spark Premium7 Days trial2 variants$7.991 Month
  • Spark Plus Monthly7 Days trial2 variants$10.001 Month
  • Spark Premium7 Days trial$11.991 Month
Show 7 more
  • Spark Pro Monthly7 Days trial$20.001 Month
  • Get Spark Premium7 Days trial$41.991 Year
  • Spark Premium1 Year trial2 variants$59.991 Year
  • Get Spark Premium7 Days trial$59.991 Year
  • Spark Plus Annual7 Days trial$99.001 Year
  • Get Spark Premium7 Days trial$119.991 Year
  • Spark Pro Annual7 Days trial$199.001 Year
One-time3
  • Regular Powerbank$4.99
  • Big Powerbank$9.99
  • Huge Powerbank$19.99
3 purchases

SuStash

Subscriptions2
  • SuStash Pro Monthly$1.991 Month
  • SuStash Pro Yearly$9.991 Year
One-time1
  • SuStash Pro Lifetime$24.99

Questions

Is Spark Mail free?
Spark Mail is free to download, with in-app purchases available.
Is SuStash free?
SuStash is free to download, with in-app purchases available.
Do Spark Mail or SuStash have ads?
Neither Spark Mail nor SuStash shows ads.
Which is updated more often, Spark Mail or SuStash?
Spark Mail ships an update weekly, and SuStash every 3 days. Most recently, Spark Mail was updated on October 25, 2026 and SuStash on October 9, 2026.

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