Comparison

Spark Mail vs Dev Calc

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

Dev Calc

This app assists developers and programmers with immediate numeric conversions between binary, octal, decimal, and hexadecimal formats. It also provides tools for generating color codes from RGB, HSL, and HSV values, with a color picker and preset options.

Highlights
  • Numeric conversion (Bin, Oct, Dec, Hex)
  • Signed/Unsigned options
  • Adjustable bit sizes (8, 16, 32, 64)
  • RGB, HSL, HSV color code generation
  • Color picker
  • Preset color options
Features
Read full description

You can convert numeric to Bin, Oct, Dec, Hex immediately with Signed, Unsigned. ** Introduction ** This is a calculator app to help System Developers and Programmers. Convert numeric to binary, octal, decimal, hex immediately. You can set conversion bit number and signed/unsigned, so you can adjust settings for binary, short, int, long. Also you can get clolor code for system application from RGB and Color Picker. And you can choose preset color simply. ** Overview ** - Convert numeric to binary, octal, decimal, hex immediately. - You can edit each digits for detailed confirmation. - You can get color code from RGB, HSL, HSV and Color Picker. - Using preset color, you can get color code quickly. ** Characteristics ** >> Numeric conversion - You can input numeric in binary, octal, decimal, hex. - You can choose bits size from 8bits, 16bits, 32bits, 64bits. - You can choose signed numeric or unsigned numeric. - you can edit each digits directly. >> Color code - You can see a color code in Hex, RGB, HSL and HSV. - Support alpha channel of color. - You can get a color code from RGB, HSL, HSV adjuster and Color Picker. - You can get a color code just by choosing a preset color. ** Terms of Use ** https://coconutsdevelop.com/en/terms/terms_of_use.html ** Developer website ** https://coconutsdevelop.com/

Screenshots

Spark Mail4 screens
Dev Calc4 screens

Verdict

The call

The clearest difference is rating: Spark Mail at 4.6 against Dev Calc's 2.0. Spark Mail also leads on ads (none vs shown) and update cadence (weekly vs every 2 months). Dev Calc's advantage is iOS requirement (13.0 vs 16.4). On price, review sentiment, in-app purchases and monetization model 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 Dev Calc sells 1 in-app purchase, starting at $1.99 per month. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

Spark Mail holds the better App Store score, 4.6 against 2.0. That said, the two scores are not equally well evidenced: Spark Mail has 82K ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 61% of Spark Mail's written reviews are positive against 60% of Dev Calc's.

UpkeepUpdate frequency

Spark Mail ships an update weekly, Dev Calc every 2 months. The most recent releases landed on September 25, 2026 and June 4, 2026 respectively.

Scorecard6 real differences · 5 level
Spark Mail versus Dev Calc: the parameters behind the verdict, then further details
ParameterSpark MailDev Calc
PriceFreeFree
Rating4.6 (82K ratings) — better2.0 (2 ratings)
Positive reviews61.4% of reviews — better60.0% of reviews
Number of ratings82K — better2
Update frequencyWeekly — betterEvery 2 months
AdsNo — betterYes
In-app purchasesYesYes
MonetizationFree with in-app purchasesFree with in-app purchases
Best chart rank#136 — better—
DevicesiPhone, iPad, Apple WatchiPhone, iPad, iPod
Requires iOS16.413.0 — better
Further details — not scored
Size382 MB51 MB
Age rating4+4+
DeveloperReaddle Technologies LimitedToshiya Hondo

Customer experience

Spark Mail

All ratings82,493 ratings
Positive91.2%
Neutral3.3%
Negative5.5%
Written reviews3,143 reviews
Positive61.4%
Neutral10.4%
Negative28.1%

Dev Calc

All ratings2 ratings
Positive0.0%
Neutral0.0%
Negative100.0%
Written reviews5 reviews
Positive60.0%
Neutral0.0%
Negative40.0%

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

Dev Calc

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
1 purchases

Dev Calc

Subscriptions1
  • Remove Ads (Monthly)$1.991 Month

Questions

Is Spark Mail free?
Spark Mail is free to download, with in-app purchases available.
Is Dev Calc free?
Dev Calc is free to download, with in-app purchases available.
Which has better reviews, Spark Mail or Dev Calc?
Spark Mail is rated higher. Spark Mail averages 4.6 out of 5 from 82K ratings, while Dev Calc averages 2.0 from 2 ratings.
Do Spark Mail or Dev Calc have ads?
Dev Calc shows ads; Spark Mail does not.
Which is updated more often, Spark Mail or Dev Calc?
Spark Mail ships an update weekly, and Dev Calc every 2 months. Most recently, Spark Mail was updated on September 25, 2026 and Dev Calc on June 4, 2026.

Other comparisons